The ability to place solder balls onto vias on a double-sided flexible substrate and mass reflow these solder balls in a conveyor oven would be a rapid and low cost method of attaching the solder balls to the substrate. This procedure, however, is not currently possible since many of the vias are connected directly to the ground plane and so when a solder ball is placed onto the via and heated, it collapses and spills from the via onto the ground plane. The current procedure for attaching solder balls to double-sided metal circuitry is to weld the solder balls onto the vias one at a time with controlled pulse heating. This method produces good results but is slow and costly. Another method is to selectively deposit a solder mask onto the ground plane before mass reflow to prevent spilling of solder at ground plane vias. However, this method adds a process step and is also costly.